1 //===-- llvm/Metadata.h - Metadata definitions ------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 /// @file 11 /// This file contains the declarations for metadata subclasses. 12 /// They represent the different flavors of metadata that live in LLVM. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #ifndef LLVM_IR_METADATA_H 17 #define LLVM_IR_METADATA_H 18 19 #include "llvm/ADT/ArrayRef.h" 20 #include "llvm/ADT/FoldingSet.h" 21 #include "llvm/ADT/ilist_node.h" 22 #include "llvm/ADT/iterator_range.h" 23 #include "llvm/IR/Value.h" 24 25 namespace llvm { 26 class LLVMContext; 27 class Module; 28 template<typename ValueSubClass, typename ItemParentClass> 29 class SymbolTableListTraits; 30 31 32 enum LLVMConstants : uint32_t { 33 DEBUG_METADATA_VERSION = 1 // Current debug info version number. 34 }; 35 36 //===----------------------------------------------------------------------===// 37 /// MDString - a single uniqued string. 38 /// These are used to efficiently contain a byte sequence for metadata. 39 /// MDString is always unnamed. 40 class MDString : public Value { 41 virtual void anchor(); 42 MDString(const MDString &) LLVM_DELETED_FUNCTION; 43 44 explicit MDString(LLVMContext &C); 45 public: 46 static MDString *get(LLVMContext &Context, StringRef Str); 47 static MDString *get(LLVMContext &Context, const char *Str) { 48 return get(Context, Str ? StringRef(Str) : StringRef()); 49 } 50 51 StringRef getString() const { return getName(); } 52 53 unsigned getLength() const { return (unsigned)getName().size(); } 54 55 typedef StringRef::iterator iterator; 56 57 /// begin() - Pointer to the first byte of the string. 58 iterator begin() const { return getName().begin(); } 59 60 /// end() - Pointer to one byte past the end of the string. 61 iterator end() const { return getName().end(); } 62 63 /// Methods for support type inquiry through isa, cast, and dyn_cast: 64 static bool classof(const Value *V) { 65 return V->getValueID() == MDStringVal; 66 } 67 }; 68 69 70 class MDNodeOperand; 71 72 //===----------------------------------------------------------------------===// 73 /// MDNode - a tuple of other values. 74 class MDNode : public Value, public FoldingSetNode { 75 MDNode(const MDNode &) LLVM_DELETED_FUNCTION; 76 void operator=(const MDNode &) LLVM_DELETED_FUNCTION; 77 friend class MDNodeOperand; 78 friend class LLVMContextImpl; 79 friend struct FoldingSetTrait<MDNode>; 80 81 /// Hash - If the MDNode is uniqued cache the hash to speed up lookup. 82 unsigned Hash; 83 84 /// NumOperands - This many 'MDNodeOperand' items are co-allocated onto the 85 /// end of this MDNode. 86 unsigned NumOperands; 87 88 // Subclass data enums. 89 enum { 90 /// FunctionLocalBit - This bit is set if this MDNode is function local. 91 /// This is true when it (potentially transitively) contains a reference to 92 /// something in a function, like an argument, basicblock, or instruction. 93 FunctionLocalBit = 1 << 0, 94 95 /// NotUniquedBit - This is set on MDNodes that are not uniqued because they 96 /// have a null operand. 97 NotUniquedBit = 1 << 1, 98 99 /// DestroyFlag - This bit is set by destroy() so the destructor can assert 100 /// that the node isn't being destroyed with a plain 'delete'. 101 DestroyFlag = 1 << 2 102 }; 103 104 // FunctionLocal enums. 105 enum FunctionLocalness { 106 FL_Unknown = -1, 107 FL_No = 0, 108 FL_Yes = 1 109 }; 110 111 /// replaceOperand - Replace each instance of F from the operand list of this 112 /// node with T. 113 void replaceOperand(MDNodeOperand *Op, Value *NewVal); 114 ~MDNode(); 115 116 MDNode(LLVMContext &C, ArrayRef<Value*> Vals, bool isFunctionLocal); 117 118 static MDNode *getMDNode(LLVMContext &C, ArrayRef<Value*> Vals, 119 FunctionLocalness FL, bool Insert = true); 120 public: 121 // Constructors and destructors. 122 static MDNode *get(LLVMContext &Context, ArrayRef<Value*> Vals); 123 // getWhenValsUnresolved - Construct MDNode determining function-localness 124 // from isFunctionLocal argument, not by analyzing Vals. 125 static MDNode *getWhenValsUnresolved(LLVMContext &Context, 126 ArrayRef<Value*> Vals, 127 bool isFunctionLocal); 128 129 static MDNode *getIfExists(LLVMContext &Context, ArrayRef<Value*> Vals); 130 131 /// getTemporary - Return a temporary MDNode, for use in constructing 132 /// cyclic MDNode structures. A temporary MDNode is not uniqued, 133 /// may be RAUW'd, and must be manually deleted with deleteTemporary. 134 static MDNode *getTemporary(LLVMContext &Context, ArrayRef<Value*> Vals); 135 136 /// deleteTemporary - Deallocate a node created by getTemporary. The 137 /// node must not have any users. 138 static void deleteTemporary(MDNode *N); 139 140 /// replaceOperandWith - Replace a specific operand. 141 void replaceOperandWith(unsigned i, Value *NewVal); 142 143 /// getOperand - Return specified operand. 144 Value *getOperand(unsigned i) const LLVM_READONLY; 145 146 /// getNumOperands - Return number of MDNode operands. 147 unsigned getNumOperands() const { return NumOperands; } 148 149 /// isFunctionLocal - Return whether MDNode is local to a function. 150 bool isFunctionLocal() const { 151 return (getSubclassDataFromValue() & FunctionLocalBit) != 0; 152 } 153 154 // getFunction - If this metadata is function-local and recursively has a 155 // function-local operand, return the first such operand's parent function. 156 // Otherwise, return null. getFunction() should not be used for performance- 157 // critical code because it recursively visits all the MDNode's operands. 158 const Function *getFunction() const; 159 160 /// Profile - calculate a unique identifier for this MDNode to collapse 161 /// duplicates 162 void Profile(FoldingSetNodeID &ID) const; 163 164 /// Methods for support type inquiry through isa, cast, and dyn_cast: 165 static bool classof(const Value *V) { 166 return V->getValueID() == MDNodeVal; 167 } 168 169 /// Check whether MDNode is a vtable access. 170 bool isTBAAVtableAccess() const; 171 172 /// Methods for metadata merging. 173 static MDNode *getMostGenericTBAA(MDNode *A, MDNode *B); 174 static MDNode *getMostGenericFPMath(MDNode *A, MDNode *B); 175 static MDNode *getMostGenericRange(MDNode *A, MDNode *B); 176 private: 177 // destroy - Delete this node. Only when there are no uses. 178 void destroy(); 179 180 bool isNotUniqued() const { 181 return (getSubclassDataFromValue() & NotUniquedBit) != 0; 182 } 183 void setIsNotUniqued(); 184 185 // Shadow Value::setValueSubclassData with a private forwarding method so that 186 // any future subclasses cannot accidentally use it. 187 void setValueSubclassData(unsigned short D) { 188 Value::setValueSubclassData(D); 189 } 190 }; 191 192 //===----------------------------------------------------------------------===// 193 /// NamedMDNode - a tuple of MDNodes. Despite its name, a NamedMDNode isn't 194 /// itself an MDNode. NamedMDNodes belong to modules, have names, and contain 195 /// lists of MDNodes. 196 class NamedMDNode : public ilist_node<NamedMDNode> { 197 friend class SymbolTableListTraits<NamedMDNode, Module>; 198 friend struct ilist_traits<NamedMDNode>; 199 friend class LLVMContextImpl; 200 friend class Module; 201 NamedMDNode(const NamedMDNode &) LLVM_DELETED_FUNCTION; 202 203 std::string Name; 204 Module *Parent; 205 void *Operands; // SmallVector<TrackingVH<MDNode>, 4> 206 207 void setParent(Module *M) { Parent = M; } 208 209 explicit NamedMDNode(const Twine &N); 210 211 template<class T1, class T2> 212 class op_iterator_impl : 213 public std::iterator<std::bidirectional_iterator_tag, T2> { 214 const NamedMDNode *Node; 215 unsigned Idx; 216 op_iterator_impl(const NamedMDNode *N, unsigned i) : Node(N), Idx(i) { } 217 218 friend class NamedMDNode; 219 220 public: 221 op_iterator_impl() : Node(nullptr), Idx(0) { } 222 223 bool operator==(const op_iterator_impl &o) const { return Idx == o.Idx; } 224 bool operator!=(const op_iterator_impl &o) const { return Idx != o.Idx; } 225 op_iterator_impl &operator++() { 226 ++Idx; 227 return *this; 228 } 229 op_iterator_impl operator++(int) { 230 op_iterator_impl tmp(*this); 231 operator++(); 232 return tmp; 233 } 234 op_iterator_impl &operator--() { 235 --Idx; 236 return *this; 237 } 238 op_iterator_impl operator--(int) { 239 op_iterator_impl tmp(*this); 240 operator--(); 241 return tmp; 242 } 243 244 T1 operator*() const { return Node->getOperand(Idx); } 245 }; 246 247 public: 248 /// eraseFromParent - Drop all references and remove the node from parent 249 /// module. 250 void eraseFromParent(); 251 252 /// dropAllReferences - Remove all uses and clear node vector. 253 void dropAllReferences(); 254 255 /// ~NamedMDNode - Destroy NamedMDNode. 256 ~NamedMDNode(); 257 258 /// getParent - Get the module that holds this named metadata collection. 259 inline Module *getParent() { return Parent; } 260 inline const Module *getParent() const { return Parent; } 261 262 /// getOperand - Return specified operand. 263 MDNode *getOperand(unsigned i) const; 264 265 /// getNumOperands - Return the number of NamedMDNode operands. 266 unsigned getNumOperands() const; 267 268 /// addOperand - Add metadata operand. 269 void addOperand(MDNode *M); 270 271 /// getName - Return a constant reference to this named metadata's name. 272 StringRef getName() const; 273 274 /// print - Implement operator<< on NamedMDNode. 275 void print(raw_ostream &ROS) const; 276 277 /// dump() - Allow printing of NamedMDNodes from the debugger. 278 void dump() const; 279 280 // --------------------------------------------------------------------------- 281 // Operand Iterator interface... 282 // 283 typedef op_iterator_impl<MDNode*, MDNode> op_iterator; 284 op_iterator op_begin() { return op_iterator(this, 0); } 285 op_iterator op_end() { return op_iterator(this, getNumOperands()); } 286 287 typedef op_iterator_impl<const MDNode*, MDNode> const_op_iterator; 288 const_op_iterator op_begin() const { return const_op_iterator(this, 0); } 289 const_op_iterator op_end() const { return const_op_iterator(this, getNumOperands()); } 290 291 inline iterator_range<op_iterator> operands() { 292 return iterator_range<op_iterator>(op_begin(), op_end()); 293 } 294 inline iterator_range<const_op_iterator> operands() const { 295 return iterator_range<const_op_iterator>(op_begin(), op_end()); 296 } 297 }; 298 299 } // end llvm namespace 300 301 #endif 302
